Letting Off Some Steam

(21 November 2017) At 5:05 pm on Tuesday afternoon, 21 November 2017, Bali’s Mount Agung began spewing clouds of gray smoke to a height estimated at 700-meters above the 3,031-meter mountain’s peak.

The billowing cloud of steam, carbon dioxide and volcanic ash was traveling in a southeasterly direction.

The latest eruption occurring several weeks of reduced seismic activity surrounding the volcano is viewed by experts observers from the Geologic Disaster Mitigation Agency (PVMBG) as a “phreatic” or “cold” eruption resulting when water penetrates cracks and vents on the mountain’s surface producing minor localized explosions that send steam and sulphur dioxide into the atmosphere together with moderate amounts of volcanic ash.

Experts generally view phreatic eruptions as a separate phenomenon from the more explosive and destructive magmatic eruptions when reservoirs of highly heated magma and lava are ejected during an eruption.

Following the latest eruption the PVMBG has not raised its current “Siaga – Level III” alert state of readiness and has reminded the public to stay out of the “red zone” that demarcates an area between 6.0 and 7.5 kilometers from the volcano’s peak. People working and living outside the above radius are not considered to be at danger.

Disaster mitigation officials and a network of sirens are on stand-by near the Mountain’s foothills to immediately advise the public and provide assistance if there is any sudden change in the alert status of the volcano.

Prevailing winds at the time of Tuesday’s eruption were blowing in a south – southeasterly direction.

People in the area have been given face masks to prevent respiratory problems should the volume of volcanic dust emitted from the mountain increase.

The Bali Tourism Board (BTB) Mount Agung Task Force is urging the public to monitor official sources, such as the Bali Tourism Board, PVMBG and MAGMA Indonesia and not be influenced by dramatic “hoax” reports emanating from the Social Network and a number of foreign news agency.

3-4 hours after the eruption of Mount Agung on Tuesday afternoon, flights to and from Bali’s Ngurah Rai Airport, located more than 60 kilometers south of the volcano, were operating largely to schedule with no indication of flight delays or cancellations linked to the eruption.

The World Organization of Volcanic Observatories (WOVO) has an “orange” color warning in place for Mount Agung. The WOVO rating is used by aviators with ”orange” – the second highest alert level indicating the volcano is exhibiting an increased likelihood of an eruption but with little or no volcanic ash being emitted into the atmosphere.

Estimates at sunset on Tuesday put the ash-cloud top at around 12294 FT (3842 M) above sea level, warning the height might more than can be easily observed. The current ash cloud is moving to the east- southeast of the volcano.